The ASBMB story notes that nanopore technology depends on differences in charges on either side of the membrane to force DNA or RNA through the hole. This is one reason why proteins pose such a challenge.
“Think of a cell as a miniature city, with proteins as its inhabitants. Each protein-resident has a unique identity, its own characteristics, and function. If there was a database cataloging the fingerprints, job profiles, and talents of the city’s inhabitants, such a database would undoubtedly be invaluable!” said Behzad Mehrafrooz, PhD (above), Graduate Research Assistant at University of Illinois at Urbana-Champaign in an article he penned for the university website. This research should be of interest to the many clinical laboratories that do protein testing. (Photo copyright: University of Illinois.)
How the Maglia Process Works
In a Groningen University news story, Maglia said protein is “like cooked spaghetti. These long strands want to be disorganized. They do not want to be pushed through this tiny hole.”
His technique, developed in collaboration with researchers at the University of Rome Tor Vergata, uses electrically charged ions to drag the protein through the hole.
“We didn’t know whether the flow would be strong enough,” Maglia stated in the news story. “Furthermore, these ions want to move both ways, but by attaching a lot of charge on the nanopore itself, we were able to make it directional.”
The researchers tested the technology on what Maglia described as a “difficult protein” with many negative charges that would tend to make it resistant to flow.
“Previously, only easy-to-thread proteins were analyzed,” he said in the news story. “But we gave ourselves one of the most difficult proteins as a test. And it worked!”
Maglia now says that he intends to commercialize the technology through a new startup called Portal Biotech.
Detecting Post-Translational Modifications in the UK
In another recent study, researchers at the University of Oxford reported that they have adapted nanopore technology to detect post-translational modifications (PTMs) in protein chains. The term refers to changes made to proteins after they have been transcribed from DNA, explained an Oxford news story.
“The ability to pinpoint and identify post-translational modifications and other protein variations at the single-molecule level holds immense promise for advancing our understanding of cellular functions and molecular interactions,” said contributing author Hagan Bayley, PhD, Professor of Chemical Biology at University of Oxford, in the news story. “It may also open new avenues for personalized medicine, diagnostics, and therapeutic interventions.”
Bayley is the founder of Oxford Nanopore Technologies, a genetic sequencing company in the UK that develops and markets nanopore sequencing products.
The news story notes that the new technique could be integrated into existing nanopore sequencing devices. “This could facilitate point-of-care diagnostics, enabling the personalized detection of specific protein variants associated with diseases including cancer and neurodegenerative disorders,” the story states.
In another recent study, researchers at the University of Washington reported that they have developed their own method for protein sequencing with nanopore technology.
“This opens up the possibility for barcode sequencing at the protein level for highly multiplexed assays, PTM monitoring, and protein identification!” Motone wrote.
Single-cell proteomics, enabled by nanopore protein sequencing technology, “could provide higher sensitivity and wider throughput, digital quantification, and novel data modalities compared to the current gold standard of protein MS [mass spectrometry],” they wrote. “The accessibility of these tools to a broader range of researchers and clinicians is also expected to increase with simpler instrumentation, less expertise needed, and lower costs.”
There are approximately 20,000 human genes. However, there are many more proteins. Thus, there is strong interest in understanding the human proteome and the role it plays in health and disease.
Technology that makes protein testing faster, more accurate, and less costly—especially with a handheld analyzer—would be a boon to the study of proteomics. And it would give clinical laboratories new diagnostic tools and bring some of that testing to point-of-care settings like doctor’s offices.
Japanese scientists who developed the detection method hope to use it to create ‘easy testing kits that anyone can use’
What do ostriches and humans have in common during the current COVID-19 pandemic? The unexpected answer is that ostrich antibodies can be used to identify humans infected with COVID-19. If proven viable in healthcare settings, the possibility exists that new clinical laboratory tests could be developed based on wearable diagnostics technologies that pathologists would interpret for doctors and patients.
According to Study Finds, scientists at Kyoto Prefectural University in Japan have created a removable mask filter that, when sprayed with a fluorescent dye coated with antibodies extracted from ostrich eggs, will glow under UV light when COVID-19 is detected. The discovery by Yasuhiro Tsukamoto, PhD (above), President of Kyoto Prefectural University, and his researchers could lead to development of low-cost at home COVID-19 testing kits using the same ostrich-antibody-based technique. (Photo copyright: Kyoto Prefectural University/Reuters.)
The KPU scientists conducted a small study with 32 COVID-19 patients over a 10-day span. The surgical-style masks they wore later glowed around the nose and mouth areas but became dimmer over time as their viral load decreased.
“The ostrich antibody for corona placed on the mouth filter of the mask captures the coronavirus in coughing, sneezing, and water,” the researchers explained in Study Finds.
Tsukamoto himself learned he had contracted COVID-19 after wearing a prototype mask and noticing it glowed under UV light. A PCR test later confirmed his diagnosis, Kyodo News reported.
The KPU team “hopes to further develop the masks so they will glow automatically, without special lighting, if the [COVID-19] virus is detected.” Reuters noted in its coverage of the ostrich-antibody masks.
Making Medicine from Ostrich Antibodies
A profile in Audubon noted that Tsukamoto, who also serves as a veterinary medicine professor at Kyoto Prefectural University, made ostriches the focus of his research since the 1990s as he looked for ways to harness the dinosaur-like bird’s properties to fight human infections. He maintains a flock of 500 captive ostriches. Each female ostrich can produce 50 to 100 eggs/year over a 50-year life span.
Tsukamoto’s research focuses on customizing the antibodies in ostrich eggs by injecting females with inactive viruses, allergens, and bacteria, and then extracting the antibodies to develop medicines for humans. Antibodies form in the egg yolks in about six weeks and can be collected without harming the parent or young.
“The idea of using ostrich antibodies for therapeutics in general is a very interesting concept, particularly because of the advantages of producing the antibodies from eggs,” Ashley St. John, PhD, an Associate Professor in Immunology, at Duke-NUS Medical School in Singapore, told Audubon.
While more clinical studies will be needed before ostrich-antibody masks reach the commercial marketplace, Tsukamoto’s team is planning to expand their experiment to 150 participants with a goal of receiving Japanese government approval to begin selling the glowing COVID-detection masks as early as 2022. But they believe the ostrich-antibody technique ultimately may lead to development of an inexpensive COVID-19 testing kit.
“We can mass-produce antibodies from ostriches at a low cost. In the future, I want to make this into an easy testing kit that anyone can use,” Tsukamoto told Kyodo News.
Harvard, MIT Also Working on COVID-19 Detecting Facemask
According to Fast Company, the MIT/Harvard COVID-19-detecting masks use the same core technology as previous paper tests for Ebola and Zika that utilize proteins and nucleic acids embedded in paper that react to target molecules.
Fast Company explained that the mask wearer launches a test by pushing a button to release a small water reservoir embedded in the mask (above). Droplets from their breath are than analyzed by the sensors in the masks, which could be adapted to test for new COVID variants or other respiratory pathogens. In addition to eliminating the use of a nasal swab, the mask-based testing system may compete with clinical laboratory-based results. (Photo copyright: Felice Frankel/MIT.)
“They would especially be useful in situations where local variant outbreaks are occurring, allowing people to conveniently test themselves at home multiple times a day,” he told Fast Company.
“It’s on par specificity and sensitivity that you will get in a state-of-the-art [medical] laboratory, but with no one there,” Luis Ruben Soenksen, PhD, Venture Builder in Artificial Intelligence and Healthcare at MIT and one of the co-authors of the Nature Biotechnology study, told Fast Company.
As the definition of “wearable diagnostic technology” broadens, pathologists and clinical laboratory scientists may see their roles expand to include helping consumers interpret data collected by point-of-care testing technology as well as performing, evaluating, and interpreting laboratory test results that come from non-traditional sources.
Though not a replacement for clinical laboratory testing, the CDC says the surveillance system will help slow spread of COVID-19 in vulnerable communities
Clinical laboratory testing for COVID-19 is receiving an ally. In mid-August, the Centers for Disease Control and Prevention (CDC) and the US Department of Health and Human Services (HHS) announced they were initiating a National Wastewater Surveillance System (NWSS) in response to the COVID-19 pandemic.
In collaboration with other federal agencies, the NWSS will work with state, local, territorial, and tribal health departments to collect data on wastewater (aka, sewage) samples throughout the United States.
The goal of the NWSS is to detect SARS-CoV-2, the coronavirus that causes COVID-19, before it spreads by detecting traces of it in local sewer systems. The level of the virus detected in wastewater can be a leading indicator of a worsening outbreak in a community, according to a CDC statement.
“Quantitative SARS-CoV-2 measurements in untreated sewage can provide information on changes in total COVID-19 infection in the community contributing to that wastewater treatment plant,” noted the CDC.
People infected with the coronavirus discard traces of it—whether they are symptomatic or asymptomatic—and levels of the virus in untreated sewage can provide scientists with information about the degree of outbreak in specific areas.
The NWSS will not include or monitor homes that use septic tanks or entities with decentralized systems that treat their own waste, such as hospitals, universities, and prisons.
Not a Replacement for Clinical Laboratory Testing
The CDC stressed that sewage testing is not meant to replace clinical laboratory testing, but it can be a valuable tool in communities where COVID-19 tests are underutilized or unavailable. Wastewater testing, CDC noted in its statement, could have an enormous reach as 80% of households in the US are connected to a municipal sewage system.
The CDC is not actively taking samples from wastewater, but relying on local partners to take samples, test them, and enter data into the NWSS portal for the purpose of summarizing and interpreting for public health action.
The agency predicts that participation in a national database will ensure data comparability across separate jurisdictions.
Could Testing Raw Sewage Be More Effective than Contact Tracing for Tracking COVID-19 Outbreaks?
A Yale University study published in Nature Biotechnology, titled, “Measurement of SARS-CoV-2 RNA in Wastewater Tracks Community Infection Dynamics,” detected SARS-CoV-2 concentrations in sewage sludge in New Haven, Conn., over a 10-week period earlier this year. The results of the study “show the utility of viral RNA monitoring in municipal wastewater for SARS-CoV-2 infection surveillance at a population-wide level,” the study authors noted.
The published study states that “SARS-CoV-2 RNA was detected throughout the more than 10-week study and, when adjusted for time lags, tracked the rise and fall of cases seen in SARS-CoV-2 clinical test results and local COVID-19 hospital admissions. Relative to these indicators, SARS-CoV-2 RNA concentrations in sludge were 0–2 [days] ahead of SARS-CoV-2 positive test results by date of specimen collection, 0–2 [days] ahead of the percentage of positive tests by date of specimen collection, 1–4 [days] ahead of local hospital admissions and 6–8 [days] ahead of SARS-CoV-2 positive test results by reporting date.”
The Yale researchers concluded, “Our results demonstrate that measurement of SARS-CoV-2 RNA concentrations in primary sludge provides an approach to estimate changes in COVID-19 prevalence on a population level. Sludge results were not a leading indicator compared to positive test results or percentage of positive tests by date of specimen collection. However, they led hospitalizations by 1–4 [days] and test results by report date by ~1 week. Thus, in communities where test reporting is delayed, sludge results, if analyzed and reported on the same day as sampling, can provide substantial advance notice of infection dynamics.”
Jordan Peccia, Jr., PhD (above), Professor of Chemical and Environmental Engineering at the Yale School of Engineering and Applied Science, and study author, told NBC News, “There’s still a lot more to do. We’re one of the earlier groups to have developed a robust relationship between wastewater and coronavirus cases, but this is just a first step.” He added, “It doesn’t replace contact tracing. [But] if we know a little bit ahead of time, we can raise the alarm.” (Photo copyright: Yale University.)
Sewage Testing for COVID-19 Around the World
Sewage testing can provide data to complement other collected information about COVID-19 and steer public health decision-making. However, the CDC notes that “it is not possible to reliably and accurately predict the number of infected individuals in a community based on sewage testing” and that “more data on fecal shedding by infected individuals over the course of disease are needed to better understand the limits of detection.”
Nevertheless, some experts have leaned heavily on sewage sample testing for their conclusions about the origination of the coronavirus. In August, Dark Daily reported on a theory based on finding remnants of SARS-CoV-2 in sewage systems that suggested the virus may not have originated in Wuhan, China. Analysis of sewage samples in Italy, Spain, and Brazil indicated the virus was present in those countries before the disease was known to exist outside of China. The controversy over these findings has motivated virologists to expand wastewater testing.
The creation of the NWSS by the CDC validates growing interest in new methods of testing for infectious disease. Lower cost, faster response time, more automation of genetic sequencing, and improved analytical software has enabled this type of testing to become a useful tool. It would be wise for clinical laboratory managers to monitor the expanded use of new testing technologies for infectious diseases.
This technology has potential to create a demand for pathologists to do genetic analysis as a companion diagnostic in support of physicians treating patients with gene-editing proteins
Researchers at Harvard University have demonstrated a new method to deliver gene-editing proteins into cells. This breakthrough could eventually trigger a demand for pathologists to do genetic analysis as the companion diagnostic needed to help clinicians select appropriate gene-editing therapies for their patients.
Of course, it will be several years before such a scenario is feasible. The related example are the companion diagnostic tests that clinical laboratories perform to guide a physician’s decision on an appropriate therapeutic drug. Continued development of gene-editing therapies has the potential to increase the need for pathologists and medical laboratory scientists to do genetic analysis as a companion diagnostic for patients who would benefit from a gene-editing therapy.
The Harvard University researchers used commercially available cationic lipids to deliver genome-editing proteins into cells. The system works on living animals and humans, and the technology enables scientists to precisely and easily change DNA sequences at exact locations. The full study was outlined in an October Nature Biotechnology article. (more…)
